Here is the updated patch.
* include/bits/stl_algobase.h (__niter_wrap): New.
(__copy_move_a2(_II, _II, _OI)): Use latter.
(__copy_move_backward_a2(_BI1, _BI1, _BI2)): Likewise.
(fill_n(_OI, _Size, const _Tp&)): Likewise.
(equal(_II1, _II1, _II2)): Use __glibcxx_requires_can_increment.
* include/debug/stl_iterator.h
(std::__niter_base(const __gnu_cxx::_Safe_iterator<
__gnu_cxx::__normal_iterator<>, _Sequence>&)): New declaration.
* include/debug/vector (__niter_base(const __gnu_cxx::_Safe_iterator<
__gnu_cxx::__normal_iterator<>, _Sequence>&)): New.
Ok to commit ?
On 02/07/2018 13:57, Jonathan Wakely wrote:
On 01/07/18 21:20 +0200, François Dumont wrote:
Here is a new proposal between yours and mine.
It is still adding a function to wrap what __niter_base unwrap, I
called it __nwrap_iter for this reason. But it takes advantage of
Since "niter" refers to __normal_iterator I think a name based on
"niter" would be better than nsomething_iter.
__niter_wrap
__niter_rewrap
__niter_lift (misuse of functional programming term?)
__niter_raise (misuse of linear algebra term?)
__make_niter
__remake_niter
knowing that __niter_base will only unwrap random access iterator to
use an expression to that will do the right thing, no matter the
original iterator type.
OK, since __niter_base only transforms types based on
__normal_iterator that seems safe to assume (in theory we could use
__normal_iterator with non-random access iterators, but we don't).
Could you please add a comment to the __nwrap_iter saying something
like:
// Reverse the __niter_base transformation to get a
// __normal_iterator back again (this assumes that __normal_iterator
// is only used to wrap random access iterators, like pointers).
I eventually found no issue in the testsuite, despite the
std::equal change. I might have had a local invalid test.
Yes, I *did* test it already :-)
diff --git a/libstdc++-v3/include/bits/stl_algobase.h
b/libstdc++-v3/include/bits/stl_algobase.h
index d429943..003ae8d 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -277,6 +277,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__niter_base(_Iterator __it)
{ return __it; }
+ // Convert an iterator of type _From to an iterator of type _To.
+ // e.g. from int* to __normal_iterator<int*, Seq>.
+ template<typename _Iterator>
+ inline _Iterator
+ __nwrap_iter(_Iterator, _Iterator, _Iterator __res)
+ { return __res; }
+
+ template<typename _From, typename _To>
+ inline _From
+ __nwrap_iter(_From __from, _To __to, _To __res)
+ { return __from + (__res - __to); }
Every time you call this function you pass it:
__nwrap_iter(x, __niter_base(x), y)
So can the __niter_base(x) call happen inside __nwrap_iter?
i.e.
template<typename _From, typename _To>
inline _From
__nwrap_iter(_From __from, _To __res)
{ return __from + (__res - __niter_base(__from)); }
diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index d429943..e5e7d15 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -277,6 +277,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__niter_base(_Iterator __it)
{ return __it; }
+ // Reverse the __niter_base transformation to get a
+ // __normal_iterator back again (this assumes that __normal_iterator
+ // is only used to wrap random access iterators, like pointers).
+ template<typename _Iterator>
+ inline _Iterator
+ __niter_wrap(_Iterator, _Iterator __res)
+ { return __res; }
+
+ template<typename _From, typename _To>
+ inline _From
+ __niter_wrap(_From __from, _To __res)
+ { return __from + (__res - __niter_base(__from)); }
+
// All of these auxiliary structs serve two purposes. (1) Replace
// calls to copy with memmove whenever possible. (Memmove, not memcpy,
// because the input and output ranges are permitted to overlap.)
@@ -419,9 +432,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
inline _OI
__copy_move_a2(_II __first, _II __last, _OI __result)
{
- return _OI(std::__copy_move_a<_IsMove>(std::__niter_base(__first),
- std::__niter_base(__last),
- std::__niter_base(__result)));
+ return std::__niter_wrap(__result,
+ std::__copy_move_a<_IsMove>(std::__niter_base(__first),
+ std::__niter_base(__last),
+ std::__niter_base(__result)));
}
/**
@@ -593,7 +607,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
inline _BI2
__copy_move_backward_a2(_BI1 __first, _BI1 __last, _BI2 __result)
{
- return _BI2(std::__copy_move_backward_a<_IsMove>
+ return std::__niter_wrap(__result,
+ std::__copy_move_backward_a<_IsMove>
(std::__niter_base(__first), std::__niter_base(__last),
std::__niter_base(__result)));
}
@@ -804,7 +819,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__glibcxx_function_requires(_OutputIteratorConcept<_OI, _Tp>)
__glibcxx_requires_can_increment(__first, __n);
- return _OI(std::__fill_n_a(std::__niter_base(__first), __n, __value));
+ return std::__niter_wrap(__first,
+ std::__fill_n_a(std::__niter_base(__first), __n, __value));
}
template<bool _BoolType>
@@ -1062,7 +1078,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
__glibcxx_function_requires(_EqualOpConcept<
typename iterator_traits<_II1>::value_type,
typename iterator_traits<_II2>::value_type>)
- __glibcxx_requires_valid_range(__first1, __last1);
+ __glibcxx_requires_can_increment_range(__first1, __last1, __first2);
return std::__equal_aux(std::__niter_base(__first1),
std::__niter_base(__last1),
diff --git a/libstdc++-v3/include/debug/stl_iterator.h b/libstdc++-v3/include/debug/stl_iterator.h
index a6a2a76..f20b000 100644
--- a/libstdc++-v3/include/debug/stl_iterator.h
+++ b/libstdc++-v3/include/debug/stl_iterator.h
@@ -120,4 +120,17 @@ namespace __gnu_debug
#endif
}
+namespace std
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ template<typename _Iterator, typename _Container, typename _Sequence>
+ _Iterator
+ __niter_base(const __gnu_debug::_Safe_iterator<
+ __gnu_cxx::__normal_iterator<_Iterator, _Container>,
+ _Sequence>&);
+
+_GLIBCXX_END_NAMESPACE_VERSION
+}
+
#endif
diff --git a/libstdc++-v3/include/debug/vector b/libstdc++-v3/include/debug/vector
index 802f4fd..ced5520 100644
--- a/libstdc++-v3/include/debug/vector
+++ b/libstdc++-v3/include/debug/vector
@@ -785,6 +785,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ return std::hash<_GLIBCXX_STD_C::vector<bool, _Alloc>>()(__b); }
};
+ template<typename _Iterator, typename _Container, typename _Sequence>
+ _Iterator
+ __niter_base(const __gnu_debug::_Safe_iterator<
+ __gnu_cxx::__normal_iterator<_Iterator, _Container>,
+ _Sequence>& __it)
+ { return std::__niter_base(__it.base()); }
+
_GLIBCXX_END_NAMESPACE_VERSION
#endif
